The present invention is a continuation-in-part of U.S. patent application, Ser. No. 09/850,269, filed May 8, 2001.
1. Field of the Invention
The present invention relates to a herbal composition for the treatment of dementia comprising Polygoni multiflori Radix (Polygonum multiflorum Thunberg) as a Principal Drug, or main component. Oriental Medicine conventionally treats dementia with ginseng as a Principal Drug. The herbal composition of the invention is efficacious against dementia, especially senile dementia, and demonstrates improved pharmacological and clinical properties, as well as fewer adverse effects, compared to conventional products.
2. Description of the Related Art
Recently the magnitude of the dementia problems as well as senile dementia has been rapidly increased. To date, dementia has no known prevention or cure except several treatment drugs showing extremely limited effects toward dementia, although there have been intensive studies in the development of drugs or foods to prevent or cure dementia in eastern or western countries. Still intensive researches have focused on senile dementia and Alzheimer's disease (AD), which refer to “progressive loss of cognition and intellectual abilities, in the biochemical, genetic and medical aspects. More specifically, main symptoms of dementia include cognitive function impairment and various mental disorders in language, judgment and perceptive vasospastic ability as well as serious difficulty in acquisition of new technologies. Personality changes and emotional restlessness soon become apparent and ultimately to death
Dementia, which adversely affects the intrinsic activity of cerebrum, is a peculiar symptom associated with the fundamental disorders of brain induced by various factors. For example, the brain was grossly shrunken in size and the expansion of the ventricle in most cases due to loss of cerebral parenchyma, a large number of cerebral cortex cells, Purkinje cells in cerebellum or eukaryotic cells at spinal cord become disappeared. The causes of these symptoms are unknown but they have been noticed to have significant relations with the level of neurotransmitter acetylcholine (ACh).
Commercially available anti-dementia agents include Cognex and Done Pezyl, which are known to inhibit the activity of acetylcholinesterase (AChE) acting to the cerebroneuronal system, thus increasing the level of cerebral acetylcholine contents, followed by improvement and treatment of cholinergic dysfunctions including dementia.
However, a majority of the conventional anti-dementia agents may produce serious cholinergic effects in the peripheral nerve with an extremely short half-life and severe side effects such as hepatotoxicity (Br. J. Psychiatry, 138, 46, 1981). Further, Cognex (9-amino-1,2,3,4-tetrahydroacridine, THA), which have been widely used for the treatment of dementia, is effective significantly in enhancement of cognitive ability in AD patients during oral administration (N, Engl. J. Med., 315, 1241, 1986) but many adverse reactions such as tremor, dizziness and cytotoxicity have still encountered. Therefore, elevating the level of the ACh can be another pharmacological concept to prevent or cure of dementia by improving the metabolism of cholinergic pathway as well as inhibiting the AchE activity.
On the other hand, Korean Patent Publication No. 1999-85202 which is the corresponding patent of U.S. Pat. No. 6,010,702 discloses herbal extracts having ginseng as a major component to inhibit against AChE activity with less severe side effects.
These herbal extracts show some effects toward dementia but they are not reliably effective. And it is only expected that the action mechanism of the herbal extracts is different from that of other dementia agents, although the herbal extracts showed some effects for senile dementia. In particular, the use of ginseng, which is a major component of the conventional herbal composition, leads to some adverse reactions such as palpitation of the heart and functional homeostatic imbalance for patients with cardiovascular diseases. Ginseng is widely known to recover intrinsic energy but it will be prohibited from using ginseng as an anti-dementia agent by the following reasons reported in the literature.
Ginseng may deprave the symptoms of patients who suffer from hypernoia, nervous prostration, hypertension or arteriosclerosis due to its side effects. And further, it is well known in oriental medicine theory that ginseng should not be used to patients suffering from pulmonary tuberculosis, asthma and cough (Professional's Handbook of Complementary and Alternative medicines, Charles W. Fetrow and Juan R. Avila, 1999, p 282–291) and recently, there are clinical reports suspecting its use.
Furthermore, compositions of such herbal extracts are administered with relatively excess amount, resulting in unexpected side effects and toxicities therefrom.